1,720,987 research outputs found
An Aspen Plus® tool for simulation of lignocellulosic biomass pyrolysis via equilibrium and ranking of the main process variables
No full textPyrolysis of non-fossil fuels is raising a growing interest in the nowadays scenario for the alternative supply of energy, fuels and chemicals. Biomass is among the most widely available and technologically promising candidate feedstocks. For simulation purposes and process design goals, kinetic-based models promise to be quite accurate in literature; however, they are computationally intensive and, more importantly, applicable only when kinetic data are available for the specific feedstock and pyrolysis equipment. Here, a different modeling approach is followed by considering that the pyrolysis reactor is under the thermodynamic equilibrium; then, the authors take advantage of the capabilities provided by the Aspen Plus® software. Therefore, this work is focused on the development of an input-output reactor model to simulate pyrolysis of a lignocellulosic biomass and to predict the effects of the main process variables. The trends of the predicted results as a function of the process operating variables are generally in accordance with those that are experimentally evident and published in literature. A limited comparison is provided against the experimental results of Honus [25]. It has to be noted that the Aspen code could not predict the composition of the liquid residue, i.e., tar
Enhancing social experiences in immersive virtual reality with artificial facial mimicry
Full text linkThe growing availability of affordable Virtual Reality (VR) hardware and the increasing interest in the Metaverse are driving the expansion of Social VR (SVR) platforms. These platforms allow users to embody avatars in immersive social virtual environments, enabling real-time interactions using consumer devices. Beyond merely replicating real-life social dynamics, SVR platforms offer opportunities to surpass real-world constraints by augmenting these interactions. One example of such augmentation is Artificial Facial Mimicry (AFM), which holds significant potential to enhance social experiences. Mimicry, the unconscious imitation of verbal and non-verbal behaviors, has been shown to positively affect human-agent interactions, yet its role in avatar-mediated human-to-human communication remains under-explored. AFM presents various possibilities, such as amplifying emotional expressions, or substituting one emotion for another to better align with the context. Furthermore, AFM can address the limitations of current facial tracking technologies in fully capturing users' emotions. To investigate the potential benefits of AFM in SVR, an automated AM system was developed. This system provides AFM, along with other kinds of head mimicry (nodding and eye contact), and it is compatible with consumer VR devices equipped with facial tracking. This system was deployed within a test-bench immersive SVR application. A between-dyads user study was conducted to assess the potential benefits of AFM for interpersonal communication while maintaining avatar behavioral naturalness, comparing the experiences of pairs of participants communicating with AFM enabled against a baseline condition. Subjective measures revealed that AFM improved interpersonal closeness, aspects of social attraction, interpersonal trust, social presence, and naturalness compared to the baseline condition. These findings demonstrate AFM's positive impact on key aspects of social interaction and highlight its potential applications across various SVR domains
MetaLibrary: Towards social immersive environments for readers
No full textThe continuous integration of cutting-edge technologies in various fields such as culture and education is leading institutions towards a radical digital evolution. This work studies how one of the key actors of these domains, i.e., libraries, could exploit the digital trans- formation to reaffirm their position as primary cultural institutions in today’s society. Indeed, there is consensus that, among technologies that could be used to modernize libraries and help them to reach a wider audience, there are Artificial Intelligence (AI) and immersive media like Virtual Reality (VR). In particular, VR has been used to create social platforms that users can join from remote, experiencing virtual environments (VEs) where they can share opinions and perform activities together, thus creating a digital community. In this context, MetaLibrary was created, an immersive VE designed to let readers socialize, attend events with authors, and receive suggestions about books to read from an AI-based recommender system. Deployment is in progress in the city of Turin, Italy
Comparing technologies for conveying emotions through realistic avatars in virtual reality-based metaverse experiences
Full text linkWith the development of metaverse(s), industry and academia are searching for the best ways to represent users' avatars in shared Virtual Environments (VEs), where real-time communication between users is required. The expressiveness of avatars is crucial for transmitting emotions that are key for social presence and user experience, and are conveyed via verbal and non-verbal facial and body signals.
In this paper, two real-time modalities for conveying expressions in Virtual Reality (VR) via realistic, full-body avatars are compared by means of a user study. The first modality uses dedicated hardware (i.e., eye and facial trackers) to allow a mapping between the user’s facial expressions/eye movements and the avatar model. The second modality relies on an algorithm that, starting from an audio clip, approximates the facial motion by generating plausible lip and eye movements. The participants were requested to observe, for both the modalities, the avatar of an actor performing six scenes involving as many basic emotions. The evaluation considered mainly social presence and emotion conveyance. Results showed a clear superiority of facial tracking when compared to lip sync in conveying sadness and disgust. The same was less evident for happiness and fear. No differences were observed for anger and surprise
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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